Allow for having for_each_ref() list extra refs
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160 static struct ref_list *current_ref;
161
162 static struct ref_list *extra_refs;
163
164 static void free_ref_list(struct ref_list *list)
165 {
166 struct ref_list *next;
167 for ( ; list; list = next) {
168 next = list->next;
169 free(list);
170 }
171 }
172
173 static void invalidate_cached_refs(void)
174 {
175 struct cached_refs *ca = &cached_refs;
176
177 if (ca->did_loose && ca->loose)
178 free_ref_list(ca->loose);
179 if (ca->did_packed && ca->packed)
180 free_ref_list(ca->packed);
181 ca->loose = ca->packed = NULL;
182 ca->did_loose = ca->did_packed = 0;
183 }
184
185 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
186 {
187 struct ref_list *list = NULL;
188 struct ref_list *last = NULL;
189 char refline[PATH_MAX];
190 int flag = REF_ISPACKED;
191
192 while (fgets(refline, sizeof(refline), f)) {
193 unsigned char sha1[20];
194 const char *name;
195 static const char header[] = "# pack-refs with:";
196
197 if (!strncmp(refline, header, sizeof(header)-1)) {
198 const char *traits = refline + sizeof(header) - 1;
199 if (strstr(traits, " peeled "))
200 flag |= REF_KNOWS_PEELED;
201 /* perhaps other traits later as well */
202 continue;
203 }
204
205 name = parse_ref_line(refline, sha1);
206 if (name) {
207 list = add_ref(name, sha1, flag, list, &last);
208 continue;
209 }
210 if (last &&
211 refline[0] == '^' &&
212 strlen(refline) == 42 &&
213 refline[41] == '\n' &&
214 !get_sha1_hex(refline + 1, sha1))
215 hashcpy(last->peeled, sha1);
216 }
217 cached_refs->packed = sort_ref_list(list);
218 }
219
220 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
221 {
222 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
223 }
224
225 void clear_extra_refs(void)
226 {
227 free_ref_list(extra_refs);
228 extra_refs = NULL;
229 }
230
231 static struct ref_list *get_packed_refs(void)
232 {
233 if (!cached_refs.did_packed) {
234 FILE *f = fopen(git_path("packed-refs"), "r");
235 cached_refs.packed = NULL;
236 if (f) {
237 read_packed_refs(f, &cached_refs);
238 fclose(f);
239 }
240 cached_refs.did_packed = 1;
241 }
242 return cached_refs.packed;
243 }
244
245 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
246 {
247 DIR *dir = opendir(git_path("%s", base));
248
249 if (dir) {
250 struct dirent *de;
251 int baselen = strlen(base);
252 char *ref = xmalloc(baselen + 257);
253
254 memcpy(ref, base, baselen);
255 if (baselen && base[baselen-1] != '/')
256 ref[baselen++] = '/';
257
258 while ((de = readdir(dir)) != NULL) {
259 unsigned char sha1[20];
260 struct stat st;
261 int flag;
262 int namelen;
263
264 if (de->d_name[0] == '.')
265 continue;
266 namelen = strlen(de->d_name);
267 if (namelen > 255)
268 continue;
269 if (has_extension(de->d_name, ".lock"))
270 continue;
271 memcpy(ref + baselen, de->d_name, namelen+1);
272 if (stat(git_path("%s", ref), &st) < 0)
273 continue;
274 if (S_ISDIR(st.st_mode)) {
275 list = get_ref_dir(ref, list);
276 continue;
277 }
278 if (!resolve_ref(ref, sha1, 1, &flag)) {
279 error("%s points nowhere!", ref);
280 continue;
281 }
282 list = add_ref(ref, sha1, flag, list, NULL);
283 }
284 free(ref);
285 closedir(dir);
286 }
287 return sort_ref_list(list);
288 }
289
290 static struct ref_list *get_loose_refs(void)
291 {
292 if (!cached_refs.did_loose) {
293 cached_refs.loose = get_ref_dir("refs", NULL);
294 cached_refs.did_loose = 1;
295 }
296 return cached_refs.loose;
297 }
298
299 /* We allow "recursive" symbolic refs. Only within reason, though */
300 #define MAXDEPTH 5
301 #define MAXREFLEN (1024)
302
303 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
304 {
305 FILE *f;
306 struct cached_refs refs;
307 struct ref_list *ref;
308 int retval;
309
310 strcpy(name + pathlen, "packed-refs");
311 f = fopen(name, "r");
312 if (!f)
313 return -1;
314 read_packed_refs(f, &refs);
315 fclose(f);
316 ref = refs.packed;
317 retval = -1;
318 while (ref) {
319 if (!strcmp(ref->name, refname)) {
320 retval = 0;
321 memcpy(result, ref->sha1, 20);
322 break;
323 }
324 ref = ref->next;
325 }
326 free_ref_list(refs.packed);
327 return retval;
328 }
329
330 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
331 {
332 int fd, len = strlen(refname);
333 char buffer[128], *p;
334
335 if (recursion > MAXDEPTH || len > MAXREFLEN)
336 return -1;
337 memcpy(name + pathlen, refname, len+1);
338 fd = open(name, O_RDONLY);
339 if (fd < 0)
340 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
341
342 len = read(fd, buffer, sizeof(buffer)-1);
343 close(fd);
344 if (len < 0)
345 return -1;
346 while (len && isspace(buffer[len-1]))
347 len--;
348 buffer[len] = 0;
349
350 /* Was it a detached head or an old-fashioned symlink? */
351 if (!get_sha1_hex(buffer, result))
352 return 0;
353
354 /* Symref? */
355 if (strncmp(buffer, "ref:", 4))
356 return -1;
357 p = buffer + 4;
358 while (isspace(*p))
359 p++;
360
361 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
362 }
363
364 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
365 {
366 int len = strlen(path), retval;
367 char *gitdir;
368
369 while (len && path[len-1] == '/')
370 len--;
371 if (!len)
372 return -1;
373 gitdir = xmalloc(len + MAXREFLEN + 8);
374 memcpy(gitdir, path, len);
375 memcpy(gitdir + len, "/.git/", 7);
376
377 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
378 free(gitdir);
379 return retval;
380 }
381
382 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
383 {
384 int depth = MAXDEPTH;
385 ssize_t len;
386 char buffer[256];
387 static char ref_buffer[256];
388
389 if (flag)
390 *flag = 0;
391
392 for (;;) {
393 const char *path = git_path("%s", ref);
394 struct stat st;
395 char *buf;
396 int fd;
397
398 if (--depth < 0)
399 return NULL;
400
401 /* Special case: non-existing file.
402 * Not having the refs/heads/new-branch is OK
403 * if we are writing into it, so is .git/HEAD
404 * that points at refs/heads/master still to be
405 * born. It is NOT OK if we are resolving for
406 * reading.
407 */
408 if (lstat(path, &st) < 0) {
409 struct ref_list *list = get_packed_refs();
410 while (list) {
411 if (!strcmp(ref, list->name)) {
412 hashcpy(sha1, list->sha1);
413 if (flag)
414 *flag |= REF_ISPACKED;
415 return ref;
416 }
417 list = list->next;
418 }
419 if (reading || errno != ENOENT)
420 return NULL;
421 hashclr(sha1);
422 return ref;
423 }
424
425 /* Follow "normalized" - ie "refs/.." symlinks by hand */
426 if (S_ISLNK(st.st_mode)) {
427 len = readlink(path, buffer, sizeof(buffer)-1);
428 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
429 buffer[len] = 0;
430 strcpy(ref_buffer, buffer);
431 ref = ref_buffer;
432 if (flag)
433 *flag |= REF_ISSYMREF;
434 continue;
435 }
436 }
437
438 /* Is it a directory? */
439 if (S_ISDIR(st.st_mode)) {
440 errno = EISDIR;
441 return NULL;
442 }
443
444 /*
445 * Anything else, just open it and try to use it as
446 * a ref
447 */
448 fd = open(path, O_RDONLY);
449 if (fd < 0)
450 return NULL;
451 len = read_in_full(fd, buffer, sizeof(buffer)-1);
452 close(fd);
453
454 /*
455 * Is it a symbolic ref?
456 */
457 if (len < 4 || memcmp("ref:", buffer, 4))
458 break;
459 buf = buffer + 4;
460 len -= 4;
461 while (len && isspace(*buf))
462 buf++, len--;
463 while (len && isspace(buf[len-1]))
464 len--;
465 buf[len] = 0;
466 memcpy(ref_buffer, buf, len + 1);
467 ref = ref_buffer;
468 if (flag)
469 *flag |= REF_ISSYMREF;
470 }
471 if (len < 40 || get_sha1_hex(buffer, sha1))
472 return NULL;
473 return ref;
474 }
475
476 int read_ref(const char *ref, unsigned char *sha1)
477 {
478 if (resolve_ref(ref, sha1, 1, NULL))
479 return 0;
480 return -1;
481 }
482
483 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
484 void *cb_data, struct ref_list *entry)
485 {
486 if (strncmp(base, entry->name, trim))
487 return 0;
488 if (is_null_sha1(entry->sha1))
489 return 0;
490 if (!has_sha1_file(entry->sha1)) {
491 error("%s does not point to a valid object!", entry->name);
492 return 0;
493 }
494 current_ref = entry;
495 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
496 }
497
498 int peel_ref(const char *ref, unsigned char *sha1)
499 {
500 int flag;
501 unsigned char base[20];
502 struct object *o;
503
504 if (current_ref && (current_ref->name == ref
505 || !strcmp(current_ref->name, ref))) {
506 if (current_ref->flag & REF_KNOWS_PEELED) {
507 hashcpy(sha1, current_ref->peeled);
508 return 0;
509 }
510 hashcpy(base, current_ref->sha1);
511 goto fallback;
512 }
513
514 if (!resolve_ref(ref, base, 1, &flag))
515 return -1;
516
517 if ((flag & REF_ISPACKED)) {
518 struct ref_list *list = get_packed_refs();
519
520 while (list) {
521 if (!strcmp(list->name, ref)) {
522 if (list->flag & REF_KNOWS_PEELED) {
523 hashcpy(sha1, list->peeled);
524 return 0;
525 }
526 /* older pack-refs did not leave peeled ones */
527 break;
528 }
529 list = list->next;
530 }
531 }
532
533 fallback:
534 o = parse_object(base);
535 if (o && o->type == OBJ_TAG) {
536 o = deref_tag(o, ref, 0);
537 if (o) {
538 hashcpy(sha1, o->sha1);
539 return 0;
540 }
541 }
542 return -1;
543 }
544
545 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
546 void *cb_data)
547 {
548 int retval = 0;
549 struct ref_list *packed = get_packed_refs();
550 struct ref_list *loose = get_loose_refs();
551
552 struct ref_list *extra;
553
554 for (extra = extra_refs; extra; extra = extra->next)
555 retval = do_one_ref(base, fn, trim, cb_data, extra);
556
557 while (packed && loose) {
558 struct ref_list *entry;
559 int cmp = strcmp(packed->name, loose->name);
560 if (!cmp) {
561 packed = packed->next;
562 continue;
563 }
564 if (cmp > 0) {
565 entry = loose;
566 loose = loose->next;
567 } else {
568 entry = packed;
569 packed = packed->next;
570 }
571 retval = do_one_ref(base, fn, trim, cb_data, entry);
572 if (retval)
573 goto end_each;
574 }
575
576 for (packed = packed ? packed : loose; packed; packed = packed->next) {
577 retval = do_one_ref(base, fn, trim, cb_data, packed);
578 if (retval)
579 goto end_each;
580 }
581
582 end_each:
583 current_ref = NULL;
584 return retval;
585 }
586
587 int head_ref(each_ref_fn fn, void *cb_data)
588 {
589 unsigned char sha1[20];
590 int flag;
591
592 if (resolve_ref("HEAD", sha1, 1, &flag))
593 return fn("HEAD", sha1, flag, cb_data);
594 return 0;
595 }
596
597 int for_each_ref(each_ref_fn fn, void *cb_data)
598 {
599 return do_for_each_ref("refs/", fn, 0, cb_data);
600 }
601
602 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
603 {
604 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
605 }
606
607 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
608 {
609 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
610 }
611
612 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
613 {
614 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
615 }
616
617 /*
618 * Make sure "ref" is something reasonable to have under ".git/refs/";
619 * We do not like it if:
620 *
621 * - any path component of it begins with ".", or
622 * - it has double dots "..", or
623 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
624 * - it ends with a "/".
625 */
626
627 static inline int bad_ref_char(int ch)
628 {
629 if (((unsigned) ch) <= ' ' ||
630 ch == '~' || ch == '^' || ch == ':')
631 return 1;
632 /* 2.13 Pattern Matching Notation */
633 if (ch == '?' || ch == '[') /* Unsupported */
634 return 1;
635 if (ch == '*') /* Supported at the end */
636 return 2;
637 return 0;
638 }
639
640 int check_ref_format(const char *ref)
641 {
642 int ch, level, bad_type;
643 const char *cp = ref;
644
645 level = 0;
646 while (1) {
647 while ((ch = *cp++) == '/')
648 ; /* tolerate duplicated slashes */
649 if (!ch)
650 /* should not end with slashes */
651 return CHECK_REF_FORMAT_ERROR;
652
653 /* we are at the beginning of the path component */
654 if (ch == '.')
655 return CHECK_REF_FORMAT_ERROR;
656 bad_type = bad_ref_char(ch);
657 if (bad_type) {
658 return (bad_type == 2 && !*cp)
659 ? CHECK_REF_FORMAT_WILDCARD
660 : CHECK_REF_FORMAT_ERROR;
661 }
662
663 /* scan the rest of the path component */
664 while ((ch = *cp++) != 0) {
665 bad_type = bad_ref_char(ch);
666 if (bad_type) {
667 return (bad_type == 2 && !*cp)
668 ? CHECK_REF_FORMAT_WILDCARD
669 : CHECK_REF_FORMAT_ERROR;
670 }
671 if (ch == '/')
672 break;
673 if (ch == '.' && *cp == '.')
674 return CHECK_REF_FORMAT_ERROR;
675 }
676 level++;
677 if (!ch) {
678 if (level < 2)
679 return CHECK_REF_FORMAT_ONELEVEL;
680 return CHECK_REF_FORMAT_OK;
681 }
682 }
683 }
684
685 const char *ref_rev_parse_rules[] = {
686 "%.*s",
687 "refs/%.*s",
688 "refs/tags/%.*s",
689 "refs/heads/%.*s",
690 "refs/remotes/%.*s",
691 "refs/remotes/%.*s/HEAD",
692 NULL
693 };
694
695 const char *ref_fetch_rules[] = {
696 "%.*s",
697 "refs/%.*s",
698 "refs/heads/%.*s",
699 NULL
700 };
701
702 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
703 {
704 const char **p;
705 const int abbrev_name_len = strlen(abbrev_name);
706
707 for (p = rules; *p; p++) {
708 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
709 return 1;
710 }
711 }
712
713 return 0;
714 }
715
716 static struct ref_lock *verify_lock(struct ref_lock *lock,
717 const unsigned char *old_sha1, int mustexist)
718 {
719 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
720 error("Can't verify ref %s", lock->ref_name);
721 unlock_ref(lock);
722 return NULL;
723 }
724 if (hashcmp(lock->old_sha1, old_sha1)) {
725 error("Ref %s is at %s but expected %s", lock->ref_name,
726 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
727 unlock_ref(lock);
728 return NULL;
729 }
730 return lock;
731 }
732
733 static int remove_empty_directories(const char *file)
734 {
735 /* we want to create a file but there is a directory there;
736 * if that is an empty directory (or a directory that contains
737 * only empty directories), remove them.
738 */
739 struct strbuf path;
740 int result;
741
742 strbuf_init(&path, 20);
743 strbuf_addstr(&path, file);
744
745 result = remove_dir_recursively(&path, 1);
746
747 strbuf_release(&path);
748
749 return result;
750 }
751
752 static int is_refname_available(const char *ref, const char *oldref,
753 struct ref_list *list, int quiet)
754 {
755 int namlen = strlen(ref); /* e.g. 'foo/bar' */
756 while (list) {
757 /* list->name could be 'foo' or 'foo/bar/baz' */
758 if (!oldref || strcmp(oldref, list->name)) {
759 int len = strlen(list->name);
760 int cmplen = (namlen < len) ? namlen : len;
761 const char *lead = (namlen < len) ? list->name : ref;
762 if (!strncmp(ref, list->name, cmplen) &&
763 lead[cmplen] == '/') {
764 if (!quiet)
765 error("'%s' exists; cannot create '%s'",
766 list->name, ref);
767 return 0;
768 }
769 }
770 list = list->next;
771 }
772 return 1;
773 }
774
775 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
776 {
777 char *ref_file;
778 const char *orig_ref = ref;
779 struct ref_lock *lock;
780 struct stat st;
781 int last_errno = 0;
782 int type;
783 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
784
785 lock = xcalloc(1, sizeof(struct ref_lock));
786 lock->lock_fd = -1;
787
788 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
789 if (!ref && errno == EISDIR) {
790 /* we are trying to lock foo but we used to
791 * have foo/bar which now does not exist;
792 * it is normal for the empty directory 'foo'
793 * to remain.
794 */
795 ref_file = git_path("%s", orig_ref);
796 if (remove_empty_directories(ref_file)) {
797 last_errno = errno;
798 error("there are still refs under '%s'", orig_ref);
799 goto error_return;
800 }
801 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
802 }
803 if (type_p)
804 *type_p = type;
805 if (!ref) {
806 last_errno = errno;
807 error("unable to resolve reference %s: %s",
808 orig_ref, strerror(errno));
809 goto error_return;
810 }
811 /* When the ref did not exist and we are creating it,
812 * make sure there is no existing ref that is packed
813 * whose name begins with our refname, nor a ref whose
814 * name is a proper prefix of our refname.
815 */
816 if (is_null_sha1(lock->old_sha1) &&
817 !is_refname_available(ref, NULL, get_packed_refs(), 0))
818 goto error_return;
819
820 lock->lk = xcalloc(1, sizeof(struct lock_file));
821
822 if (flags & REF_NODEREF)
823 ref = orig_ref;
824 lock->ref_name = xstrdup(ref);
825 lock->orig_ref_name = xstrdup(orig_ref);
826 ref_file = git_path("%s", ref);
827 if (lstat(ref_file, &st) && errno == ENOENT)
828 lock->force_write = 1;
829 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
830 lock->force_write = 1;
831
832 if (safe_create_leading_directories(ref_file)) {
833 last_errno = errno;
834 error("unable to create directory for %s", ref_file);
835 goto error_return;
836 }
837 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
838
839 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
840
841 error_return:
842 unlock_ref(lock);
843 errno = last_errno;
844 return NULL;
845 }
846
847 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
848 {
849 char refpath[PATH_MAX];
850 if (check_ref_format(ref))
851 return NULL;
852 strcpy(refpath, mkpath("refs/%s", ref));
853 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
854 }
855
856 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
857 {
858 switch (check_ref_format(ref)) {
859 default:
860 return NULL;
861 case 0:
862 case CHECK_REF_FORMAT_ONELEVEL:
863 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
864 }
865 }
866
867 static struct lock_file packlock;
868
869 static int repack_without_ref(const char *refname)
870 {
871 struct ref_list *list, *packed_ref_list;
872 int fd;
873 int found = 0;
874
875 packed_ref_list = get_packed_refs();
876 for (list = packed_ref_list; list; list = list->next) {
877 if (!strcmp(refname, list->name)) {
878 found = 1;
879 break;
880 }
881 }
882 if (!found)
883 return 0;
884 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
885 if (fd < 0)
886 return error("cannot delete '%s' from packed refs", refname);
887
888 for (list = packed_ref_list; list; list = list->next) {
889 char line[PATH_MAX + 100];
890 int len;
891
892 if (!strcmp(refname, list->name))
893 continue;
894 len = snprintf(line, sizeof(line), "%s %s\n",
895 sha1_to_hex(list->sha1), list->name);
896 /* this should not happen but just being defensive */
897 if (len > sizeof(line))
898 die("too long a refname '%s'", list->name);
899 write_or_die(fd, line, len);
900 }
901 return commit_lock_file(&packlock);
902 }
903
904 int delete_ref(const char *refname, const unsigned char *sha1)
905 {
906 struct ref_lock *lock;
907 int err, i, ret = 0, flag = 0;
908
909 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
910 if (!lock)
911 return 1;
912 if (!(flag & REF_ISPACKED)) {
913 /* loose */
914 i = strlen(lock->lk->filename) - 5; /* .lock */
915 lock->lk->filename[i] = 0;
916 err = unlink(lock->lk->filename);
917 if (err) {
918 ret = 1;
919 error("unlink(%s) failed: %s",
920 lock->lk->filename, strerror(errno));
921 }
922 lock->lk->filename[i] = '.';
923 }
924 /* removing the loose one could have resurrected an earlier
925 * packed one. Also, if it was not loose we need to repack
926 * without it.
927 */
928 ret |= repack_without_ref(refname);
929
930 err = unlink(git_path("logs/%s", lock->ref_name));
931 if (err && errno != ENOENT)
932 fprintf(stderr, "warning: unlink(%s) failed: %s",
933 git_path("logs/%s", lock->ref_name), strerror(errno));
934 invalidate_cached_refs();
935 unlock_ref(lock);
936 return ret;
937 }
938
939 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
940 {
941 static const char renamed_ref[] = "RENAMED-REF";
942 unsigned char sha1[20], orig_sha1[20];
943 int flag = 0, logmoved = 0;
944 struct ref_lock *lock;
945 struct stat loginfo;
946 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
947
948 if (S_ISLNK(loginfo.st_mode))
949 return error("reflog for %s is a symlink", oldref);
950
951 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
952 return error("refname %s not found", oldref);
953
954 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
955 return 1;
956
957 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
958 return 1;
959
960 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
961 if (!lock)
962 return error("unable to lock %s", renamed_ref);
963 lock->force_write = 1;
964 if (write_ref_sha1(lock, orig_sha1, logmsg))
965 return error("unable to save current sha1 in %s", renamed_ref);
966
967 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
968 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
969 oldref, strerror(errno));
970
971 if (delete_ref(oldref, orig_sha1)) {
972 error("unable to delete old %s", oldref);
973 goto rollback;
974 }
975
976 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
977 if (errno==EISDIR) {
978 if (remove_empty_directories(git_path("%s", newref))) {
979 error("Directory not empty: %s", newref);
980 goto rollback;
981 }
982 } else {
983 error("unable to delete existing %s", newref);
984 goto rollback;
985 }
986 }
987
988 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
989 error("unable to create directory for %s", newref);
990 goto rollback;
991 }
992
993 retry:
994 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
995 if (errno==EISDIR || errno==ENOTDIR) {
996 /*
997 * rename(a, b) when b is an existing
998 * directory ought to result in ISDIR, but
999 * Solaris 5.8 gives ENOTDIR. Sheesh.
1000 */
1001 if (remove_empty_directories(git_path("logs/%s", newref))) {
1002 error("Directory not empty: logs/%s", newref);
1003 goto rollback;
1004 }
1005 goto retry;
1006 } else {
1007 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1008 newref, strerror(errno));
1009 goto rollback;
1010 }
1011 }
1012 logmoved = log;
1013
1014 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1015 if (!lock) {
1016 error("unable to lock %s for update", newref);
1017 goto rollback;
1018 }
1019
1020 lock->force_write = 1;
1021 hashcpy(lock->old_sha1, orig_sha1);
1022 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1023 error("unable to write current sha1 into %s", newref);
1024 goto rollback;
1025 }
1026
1027 return 0;
1028
1029 rollback:
1030 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1031 if (!lock) {
1032 error("unable to lock %s for rollback", oldref);
1033 goto rollbacklog;
1034 }
1035
1036 lock->force_write = 1;
1037 flag = log_all_ref_updates;
1038 log_all_ref_updates = 0;
1039 if (write_ref_sha1(lock, orig_sha1, NULL))
1040 error("unable to write current sha1 into %s", oldref);
1041 log_all_ref_updates = flag;
1042
1043 rollbacklog:
1044 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1045 error("unable to restore logfile %s from %s: %s",
1046 oldref, newref, strerror(errno));
1047 if (!logmoved && log &&
1048 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1049 error("unable to restore logfile %s from tmp-renamed-log: %s",
1050 oldref, strerror(errno));
1051
1052 return 1;
1053 }
1054
1055 int close_ref(struct ref_lock *lock)
1056 {
1057 if (close_lock_file(lock->lk))
1058 return -1;
1059 lock->lock_fd = -1;
1060 return 0;
1061 }
1062
1063 int commit_ref(struct ref_lock *lock)
1064 {
1065 if (commit_lock_file(lock->lk))
1066 return -1;
1067 lock->lock_fd = -1;
1068 return 0;
1069 }
1070
1071 void unlock_ref(struct ref_lock *lock)
1072 {
1073 /* Do not free lock->lk -- atexit() still looks at them */
1074 if (lock->lk)
1075 rollback_lock_file(lock->lk);
1076 free(lock->ref_name);
1077 free(lock->orig_ref_name);
1078 free(lock);
1079 }
1080
1081 /*
1082 * copy the reflog message msg to buf, which has been allocated sufficiently
1083 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1084 * because reflog file is one line per entry.
1085 */
1086 static int copy_msg(char *buf, const char *msg)
1087 {
1088 char *cp = buf;
1089 char c;
1090 int wasspace = 1;
1091
1092 *cp++ = '\t';
1093 while ((c = *msg++)) {
1094 if (wasspace && isspace(c))
1095 continue;
1096 wasspace = isspace(c);
1097 if (wasspace)
1098 c = ' ';
1099 *cp++ = c;
1100 }
1101 while (buf < cp && isspace(cp[-1]))
1102 cp--;
1103 *cp++ = '\n';
1104 return cp - buf;
1105 }
1106
1107 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1108 const unsigned char *new_sha1, const char *msg)
1109 {
1110 int logfd, written, oflags = O_APPEND | O_WRONLY;
1111 unsigned maxlen, len;
1112 int msglen;
1113 char *log_file, *logrec;
1114 const char *committer;
1115
1116 if (log_all_ref_updates < 0)
1117 log_all_ref_updates = !is_bare_repository();
1118
1119 log_file = git_path("logs/%s", ref_name);
1120
1121 if (log_all_ref_updates &&
1122 (!prefixcmp(ref_name, "refs/heads/") ||
1123 !prefixcmp(ref_name, "refs/remotes/") ||
1124 !strcmp(ref_name, "HEAD"))) {
1125 if (safe_create_leading_directories(log_file) < 0)
1126 return error("unable to create directory for %s",
1127 log_file);
1128 oflags |= O_CREAT;
1129 }
1130
1131 logfd = open(log_file, oflags, 0666);
1132 if (logfd < 0) {
1133 if (!(oflags & O_CREAT) && errno == ENOENT)
1134 return 0;
1135
1136 if ((oflags & O_CREAT) && errno == EISDIR) {
1137 if (remove_empty_directories(log_file)) {
1138 return error("There are still logs under '%s'",
1139 log_file);
1140 }
1141 logfd = open(log_file, oflags, 0666);
1142 }
1143
1144 if (logfd < 0)
1145 return error("Unable to append to %s: %s",
1146 log_file, strerror(errno));
1147 }
1148
1149 adjust_shared_perm(log_file);
1150
1151 msglen = msg ? strlen(msg) : 0;
1152 committer = git_committer_info(0);
1153 maxlen = strlen(committer) + msglen + 100;
1154 logrec = xmalloc(maxlen);
1155 len = sprintf(logrec, "%s %s %s\n",
1156 sha1_to_hex(old_sha1),
1157 sha1_to_hex(new_sha1),
1158 committer);
1159 if (msglen)
1160 len += copy_msg(logrec + len - 1, msg) - 1;
1161 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1162 free(logrec);
1163 if (close(logfd) != 0 || written != len)
1164 return error("Unable to append to %s", log_file);
1165 return 0;
1166 }
1167
1168 static int is_branch(const char *refname)
1169 {
1170 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1171 }
1172
1173 int write_ref_sha1(struct ref_lock *lock,
1174 const unsigned char *sha1, const char *logmsg)
1175 {
1176 static char term = '\n';
1177 struct object *o;
1178
1179 if (!lock)
1180 return -1;
1181 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1182 unlock_ref(lock);
1183 return 0;
1184 }
1185 o = parse_object(sha1);
1186 if (!o) {
1187 error("Trying to write ref %s with nonexistant object %s",
1188 lock->ref_name, sha1_to_hex(sha1));
1189 unlock_ref(lock);
1190 return -1;
1191 }
1192 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1193 error("Trying to write non-commit object %s to branch %s",
1194 sha1_to_hex(sha1), lock->ref_name);
1195 unlock_ref(lock);
1196 return -1;
1197 }
1198 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1199 write_in_full(lock->lock_fd, &term, 1) != 1
1200 || close_ref(lock) < 0) {
1201 error("Couldn't write %s", lock->lk->filename);
1202 unlock_ref(lock);
1203 return -1;
1204 }
1205 invalidate_cached_refs();
1206 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1207 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1208 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1209 unlock_ref(lock);
1210 return -1;
1211 }
1212 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1213 /*
1214 * Special hack: If a branch is updated directly and HEAD
1215 * points to it (may happen on the remote side of a push
1216 * for example) then logically the HEAD reflog should be
1217 * updated too.
1218 * A generic solution implies reverse symref information,
1219 * but finding all symrefs pointing to the given branch
1220 * would be rather costly for this rare event (the direct
1221 * update of a branch) to be worth it. So let's cheat and
1222 * check with HEAD only which should cover 99% of all usage
1223 * scenarios (even 100% of the default ones).
1224 */
1225 unsigned char head_sha1[20];
1226 int head_flag;
1227 const char *head_ref;
1228 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1229 if (head_ref && (head_flag & REF_ISSYMREF) &&
1230 !strcmp(head_ref, lock->ref_name))
1231 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1232 }
1233 if (commit_ref(lock)) {
1234 error("Couldn't set %s", lock->ref_name);
1235 unlock_ref(lock);
1236 return -1;
1237 }
1238 unlock_ref(lock);
1239 return 0;
1240 }
1241
1242 int create_symref(const char *ref_target, const char *refs_heads_master,
1243 const char *logmsg)
1244 {
1245 const char *lockpath;
1246 char ref[1000];
1247 int fd, len, written;
1248 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1249 unsigned char old_sha1[20], new_sha1[20];
1250
1251 if (logmsg && read_ref(ref_target, old_sha1))
1252 hashclr(old_sha1);
1253
1254 if (safe_create_leading_directories(git_HEAD) < 0)
1255 return error("unable to create directory for %s", git_HEAD);
1256
1257 #ifndef NO_SYMLINK_HEAD
1258 if (prefer_symlink_refs) {
1259 unlink(git_HEAD);
1260 if (!symlink(refs_heads_master, git_HEAD))
1261 goto done;
1262 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1263 }
1264 #endif
1265
1266 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1267 if (sizeof(ref) <= len) {
1268 error("refname too long: %s", refs_heads_master);
1269 goto error_free_return;
1270 }
1271 lockpath = mkpath("%s.lock", git_HEAD);
1272 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1273 if (fd < 0) {
1274 error("Unable to open %s for writing", lockpath);
1275 goto error_free_return;
1276 }
1277 written = write_in_full(fd, ref, len);
1278 if (close(fd) != 0 || written != len) {
1279 error("Unable to write to %s", lockpath);
1280 goto error_unlink_return;
1281 }
1282 if (rename(lockpath, git_HEAD) < 0) {
1283 error("Unable to create %s", git_HEAD);
1284 goto error_unlink_return;
1285 }
1286 if (adjust_shared_perm(git_HEAD)) {
1287 error("Unable to fix permissions on %s", lockpath);
1288 error_unlink_return:
1289 unlink(lockpath);
1290 error_free_return:
1291 free(git_HEAD);
1292 return -1;
1293 }
1294
1295 #ifndef NO_SYMLINK_HEAD
1296 done:
1297 #endif
1298 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1299 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1300
1301 free(git_HEAD);
1302 return 0;
1303 }
1304
1305 static char *ref_msg(const char *line, const char *endp)
1306 {
1307 const char *ep;
1308 line += 82;
1309 ep = memchr(line, '\n', endp - line);
1310 if (!ep)
1311 ep = endp;
1312 return xmemdupz(line, ep - line);
1313 }
1314
1315 int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1316 {
1317 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1318 char *tz_c;
1319 int logfd, tz, reccnt = 0;
1320 struct stat st;
1321 unsigned long date;
1322 unsigned char logged_sha1[20];
1323 void *log_mapped;
1324 size_t mapsz;
1325
1326 logfile = git_path("logs/%s", ref);
1327 logfd = open(logfile, O_RDONLY, 0);
1328 if (logfd < 0)
1329 die("Unable to read log %s: %s", logfile, strerror(errno));
1330 fstat(logfd, &st);
1331 if (!st.st_size)
1332 die("Log %s is empty.", logfile);
1333 mapsz = xsize_t(st.st_size);
1334 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1335 logdata = log_mapped;
1336 close(logfd);
1337
1338 lastrec = NULL;
1339 rec = logend = logdata + st.st_size;
1340 while (logdata < rec) {
1341 reccnt++;
1342 if (logdata < rec && *(rec-1) == '\n')
1343 rec--;
1344 lastgt = NULL;
1345 while (logdata < rec && *(rec-1) != '\n') {
1346 rec--;
1347 if (*rec == '>')
1348 lastgt = rec;
1349 }
1350 if (!lastgt)
1351 die("Log %s is corrupt.", logfile);
1352 date = strtoul(lastgt + 1, &tz_c, 10);
1353 if (date <= at_time || cnt == 0) {
1354 tz = strtoul(tz_c, NULL, 10);
1355 if (msg)
1356 *msg = ref_msg(rec, logend);
1357 if (cutoff_time)
1358 *cutoff_time = date;
1359 if (cutoff_tz)
1360 *cutoff_tz = tz;
1361 if (cutoff_cnt)
1362 *cutoff_cnt = reccnt - 1;
1363 if (lastrec) {
1364 if (get_sha1_hex(lastrec, logged_sha1))
1365 die("Log %s is corrupt.", logfile);
1366 if (get_sha1_hex(rec + 41, sha1))
1367 die("Log %s is corrupt.", logfile);
1368 if (hashcmp(logged_sha1, sha1)) {
1369 fprintf(stderr,
1370 "warning: Log %s has gap after %s.\n",
1371 logfile, show_date(date, tz, DATE_RFC2822));
1372 }
1373 }
1374 else if (date == at_time) {
1375 if (get_sha1_hex(rec + 41, sha1))
1376 die("Log %s is corrupt.", logfile);
1377 }
1378 else {
1379 if (get_sha1_hex(rec + 41, logged_sha1))
1380 die("Log %s is corrupt.", logfile);
1381 if (hashcmp(logged_sha1, sha1)) {
1382 fprintf(stderr,
1383 "warning: Log %s unexpectedly ended on %s.\n",
1384 logfile, show_date(date, tz, DATE_RFC2822));
1385 }
1386 }
1387 munmap(log_mapped, mapsz);
1388 return 0;
1389 }
1390 lastrec = rec;
1391 if (cnt > 0)
1392 cnt--;
1393 }
1394
1395 rec = logdata;
1396 while (rec < logend && *rec != '>' && *rec != '\n')
1397 rec++;
1398 if (rec == logend || *rec == '\n')
1399 die("Log %s is corrupt.", logfile);
1400 date = strtoul(rec + 1, &tz_c, 10);
1401 tz = strtoul(tz_c, NULL, 10);
1402 if (get_sha1_hex(logdata, sha1))
1403 die("Log %s is corrupt.", logfile);
1404 if (msg)
1405 *msg = ref_msg(logdata, logend);
1406 munmap(log_mapped, mapsz);
1407
1408 if (cutoff_time)
1409 *cutoff_time = date;
1410 if (cutoff_tz)
1411 *cutoff_tz = tz;
1412 if (cutoff_cnt)
1413 *cutoff_cnt = reccnt;
1414 return 1;
1415 }
1416
1417 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1418 {
1419 const char *logfile;
1420 FILE *logfp;
1421 char buf[1024];
1422 int ret = 0;
1423
1424 logfile = git_path("logs/%s", ref);
1425 logfp = fopen(logfile, "r");
1426 if (!logfp)
1427 return -1;
1428 while (fgets(buf, sizeof(buf), logfp)) {
1429 unsigned char osha1[20], nsha1[20];
1430 char *email_end, *message;
1431 unsigned long timestamp;
1432 int len, tz;
1433
1434 /* old SP new SP name <email> SP time TAB msg LF */
1435 len = strlen(buf);
1436 if (len < 83 || buf[len-1] != '\n' ||
1437 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1438 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1439 !(email_end = strchr(buf + 82, '>')) ||
1440 email_end[1] != ' ' ||
1441 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1442 !message || message[0] != ' ' ||
1443 (message[1] != '+' && message[1] != '-') ||
1444 !isdigit(message[2]) || !isdigit(message[3]) ||
1445 !isdigit(message[4]) || !isdigit(message[5]))
1446 continue; /* corrupt? */
1447 email_end[1] = '\0';
1448 tz = strtol(message + 1, NULL, 10);
1449 if (message[6] != '\t')
1450 message += 6;
1451 else
1452 message += 7;
1453 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1454 if (ret)
1455 break;
1456 }
1457 fclose(logfp);
1458 return ret;
1459 }
1460
1461 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1462 {
1463 DIR *dir = opendir(git_path("logs/%s", base));
1464 int retval = 0;
1465
1466 if (dir) {
1467 struct dirent *de;
1468 int baselen = strlen(base);
1469 char *log = xmalloc(baselen + 257);
1470
1471 memcpy(log, base, baselen);
1472 if (baselen && base[baselen-1] != '/')
1473 log[baselen++] = '/';
1474
1475 while ((de = readdir(dir)) != NULL) {
1476 struct stat st;
1477 int namelen;
1478
1479 if (de->d_name[0] == '.')
1480 continue;
1481 namelen = strlen(de->d_name);
1482 if (namelen > 255)
1483 continue;
1484 if (has_extension(de->d_name, ".lock"))
1485 continue;
1486 memcpy(log + baselen, de->d_name, namelen+1);
1487 if (stat(git_path("logs/%s", log), &st) < 0)
1488 continue;
1489 if (S_ISDIR(st.st_mode)) {
1490 retval = do_for_each_reflog(log, fn, cb_data);
1491 } else {
1492 unsigned char sha1[20];
1493 if (!resolve_ref(log, sha1, 0, NULL))
1494 retval = error("bad ref for %s", log);
1495 else
1496 retval = fn(log, sha1, 0, cb_data);
1497 }
1498 if (retval)
1499 break;
1500 }
1501 free(log);
1502 closedir(dir);
1503 }
1504 else if (*base)
1505 return errno;
1506 return retval;
1507 }
1508
1509 int for_each_reflog(each_ref_fn fn, void *cb_data)
1510 {
1511 return do_for_each_reflog("", fn, cb_data);
1512 }
1513
1514 int update_ref(const char *action, const char *refname,
1515 const unsigned char *sha1, const unsigned char *oldval,
1516 int flags, enum action_on_err onerr)
1517 {
1518 static struct ref_lock *lock;
1519 lock = lock_any_ref_for_update(refname, oldval, flags);
1520 if (!lock) {
1521 const char *str = "Cannot lock the ref '%s'.";
1522 switch (onerr) {
1523 case MSG_ON_ERR: error(str, refname); break;
1524 case DIE_ON_ERR: die(str, refname); break;
1525 case QUIET_ON_ERR: break;
1526 }
1527 return 1;
1528 }
1529 if (write_ref_sha1(lock, sha1, action) < 0) {
1530 const char *str = "Cannot update the ref '%s'.";
1531 switch (onerr) {
1532 case MSG_ON_ERR: error(str, refname); break;
1533 case DIE_ON_ERR: die(str, refname); break;
1534 case QUIET_ON_ERR: break;
1535 }
1536 return 1;
1537 }
1538 return 0;
1539 }
1540
1541 struct ref *find_ref_by_name(struct ref *list, const char *name)
1542 {
1543 for ( ; list; list = list->next)
1544 if (!strcmp(list->name, name))
1545 return list;
1546 return NULL;
1547 }